Both :-)
Thats not quite right, 1:1.618 as a fraction is 1/2.618 or 1.618/2.618. See ratios on the Free Online Tutoring | Maths Help | chemistry Help Exam revision | My tutor | My tutoring site for a full explanation as to why this is the case....
If you say a:b=1:2 this means a/b=1/2 or a=1/2 of b. On the other hand suppose we were asked to divide say £12 in the ratio 1:2 then one part=1/3 of 12 =£4 and the other part is 2/3 of 12=£8 Notice the answers are in the ratio 1:2 as asked.
err - its under ratios in maths..... Ratios | Slide 1 of 15
Yep a is 1/2 of B but a fraction by itself pertains to the whole unless specified otherwise, therefore a ratio of 1:2 can be also written as 1/2:1 or a is 1/2 of b but these are still ratios and not fractions as they relate one number to the other. A fraction stands alone and relates to the whole of the same. if a class has 5 bys and 10 girls.
As a Fraction:
the fraction of girls is 10/15 = 2/3,
or
the fraction of boys is 5/15=1/3
As a ratio:
the ratio of boys to girls is 1:2,
or
the are half as many boys as girls,
or
there are twice as many girls as boys.
the confuson arrises as people often mix fractions into ratios to make the number easier to handle